Every year thousands of women suffer from pregnancy induced hypertension. While blood pressure during pregnancy is generally lower than in the non-pregnant state, some pregnant women will develop hypertension. Hypertension during pregnancy can have a significant impact on the mother and the fetus, including, but not limited to stroke or other cardiovascular complications. It is estimated that 7 out of every 100 pregnant women will develop toxemia/eclampsia and/or pre-eclampsia of which hypertension is the main presenting symptom. Mild toxemia, also known as preeclampsia is monitored closely and usually causes few problems for the mother or child. Of note, toxemia, and eclampsia are often used interchangeably to refer to the same condition, and will be used interchangeably throughout the application.
There is no known cause for toxemia. What is known is that toxemia starts to develop as the placenta begins to develop, although the condition may not be detected until the latter part of pregnancy. Most cases of toxemia happen with first pregnancies. Second and subsequent pregnancies are at lower risk, unless the woman is with a new partner. Since there is no known cause of toxemia, there is no way to determine if a woman is at risk for the condition before she gets pregnant.
Preeclampsia causes hypertension and proteinuria, manifesting most often after the twentieth week of pregnancy. In the past, edema was considered a diagnostic criterion. Recently, however, it has been eliminated as a requirement for diagnosis. Preeclampsia causes vasospasm, a condition in which your blood vessels squeeze and then relax almost like a muscle spasm. This causes the smooth lining of the blood vessels to become damaged and rough. Once this damage occurs, the body will send out cells to repair the damage. The cells that arrive first are platelets. As platelets and other blood products try to repair the damage, they form little clots along the blood vessel wall causing the blood vessel to become even more narrow and further decreasing blood flow to the organs. The body continually makes new platelets; however, there is a limited supply of platelets in the body at any one time. Once they have become depleted, spontaneous bleeding can occur.
Other cells passing by the damaged lining of the blood vessels break open, often spilling their toxic contents. These toxic waste products cause high blood pressure and even more damage to other organs. Vasospasm and the miniature blood clots cause further damage by decreasing blood flow and thus decreasing the oxygen supply to vital organs such as the brain, kidneys, and liver.
The term preeclampsia refers to the disease state before a seizure. Once a woman has had a seizure with this disease, it then becomes eclampsia. Eclampsia includes hypertension and proteinuria. Preeclampsia may be classified as mild or severe. Severe preeclampsia is characterized by (1) a systolic blood pressure in a known normotensive woman greater than 140-160 mm Hg or diastolic blood pressure greater than 90-110 mm Hg on 2 occasions at least 6 hours apart in a woman on bed rest and (2) the presence of significant proteinuria. Proteinuria concentration associated with preeclampsia are in the 300 mg/24 hour urine range. Marked proteinuria is defined as 5 g or more of protein in a 24-hour urine collection.
Severe preeclampsia, at times, may be associated with oliguria, cerebral or visual disturbances, pulmonary edema or cyanosis, epigastric or right upper quadrant abdominal pain, impaired liver function, thrombocytopenia, or intrauterine growth restriction. In mild preeclampsia, hypertension and proteinuria are present, but not to these extreme levels, and the patient has no evidence of other organ dysfunction. As preeclapmsia develops into eclampsia/toxemia, oliguria and other symptoms may be present. Many of the health problems associated with eclampsia/toxemia may be very dangerous to the mother and the child, and can result in severe morbidity and potentially mortality for the mother and/or the child. Toxemia may cause liver and/or kidney damage or failure. It may cause problems with eyesight and, if left untreated for too long, may cause the maternal patient to go into seizures. These seizures can lead to coma and even death. Often, the progression of these symptoms can not be stopped and full blown toxemia occurs, including kidney failure.
The etiology of preeclampsia is still unknown. Many areas have been explored including: the examination of the renin-angiotensin system, selective hormonal examination, including epinephrine, norepinephrine, and vasopressin. Further examination has included endothelin and prostaglandins, all without conclusion or an effective treatment for preeclampsia and the potential resultant eclampsia/toxemia.
Since placental delivery reverses the symptoms of preeclampsia, it suggests that the placenta may have a central role in the condition. Additionally, women with increased placental tissue for gestational age, those with hydatiform moles and/or twin or multiple pregnancies, have an increased prevalence of preeclampsia. This, therefore, leads one to consider the possibility that substances, such as human chorionic gonadotropin, which is high in a hydatiform mole, may be involved. This link between the placenta and the development of preeclampsia is key.
As the fertilized ovum begins to divide, it is known as a morula at the sixteen cell stage. As the morula enters the uterine cavity from the fallopian tube, it does not implant until day seven of gestation at which time it is termed a blastocyst. The trophoblastic cells of the blastocyst erode the uterine lining to form large pockets known as lacunae. The trophoblast now forms a divide in the cellular portion and the syncytial portion. The outside covering of the syncytial portion is known as the chorion. The chorion secretes human chorionic gonadotropin which prevents immune attack from the mother, and helps to maintain the corpus luteum of pregnancy until the maternal/fetal exchange can take place through the placenta. This is the beginning of the formation of the placenta.
The cellular trophoblast, once it begins to proliferate without proper changeover to syncytial trophoblastic activity, may cause possible syncytial demise, thus reducing the amount of steroid hormone produced, and also reducing the possibility that the placenta will form correctly. The syncytial trophoblast further proliferates to form a highly specialized trophoblast, known as an extravillous trophoblast. The extravillous trophoblast bores through the endometrium, extending to the decidua and myometrium of the uterus. These extravillous trophoblasts continue their invasion into the spiral arterioles of the uterus and replace the endothelial and muscular linings of the uterine arterioles, leading to vasodilation of the uterine vasculature. This change ensures a continued low resistance system, which potentiates maternal blood flow to the intervillous space and maintains adequate perfusion of the developing fetus.
The mechanism by which the cellular trophoblast is reduced in its proliferation such that the syncytial trophoblast can take over is the presence of proteolytic enzymes, especially that of chymotrypsin. These proteases produced by the mother, especially chymotrypsin, are able to restrain the proliferation of the cellular trophoblast and the overproduction of human chorionic gonadotropin. This mechanism was outlined by Ernest T. Krebs in 1949 (Medical Record, Vol. 162, No. 10, October 1949).
In preeclampsia, the lack of proliferation of the syncytial trophoblasts leads to a lack of extravillous trophoblasts and an improper boring into the muscular lining of the uterine arterioles. This leads to vasospasm of the arteries of the uterine endometrium and results in ischemia, anoxia, necrosis, histamine and tyramine release. With the absence of marked vasodilation and the lumen of the vessels essentially occluded, blood flow and oxygen transfer to the fetus is diminished, leading to the maternal manifestations of preeclampsia as well as the fetal manifestations of oligohydramnios and intrauterine growth restriction (IUGR).
The resultant improper placental development results in placental vascular endothelial dysfunction and a relative uteroplacental insufficiency. The vascular endothelial dysfunction results in increased permeability, hypercoagulability, and diffuse vasospasm.
The loss of protein through the kidney and excretion in the urine and the alterations in the permeability of the vascular system due to the potential endothelial dysfunction results in an increase in vascular permeability. This enhanced vascular permeability ultimately permits the proteins, especially large proteins which are large molecules, to get through the capillaries and the glomerulus of the kidney. This loss of protein creates a potential need for large amounts of protein intake during pregnancy.
With incomplete protein breakdown due to the increased permeability of the vascular system, and its ability to permit large molecules into the vascular system, the protein requirements of the body during pregnancy are even greater than in the non-pregnant state. Further, with the significant loss of protein and the resultant dearth of amino acids present in the pregnant woman, the potential exists for organ dysfunction and potential organ death.
The use of digestive enzymes can facilitate the presence of sufficient protein so as not to allow the body to go into a negative protein balance. This is highly desirable as well as necessary due to the need for proteases such that the body can facilitate formation of the placenta as well as replacement proteins which are lost by the body during the pregnancy.
In view of such findings, there is need for a method of treating those with preeclampsia such that the development of eclampsia/toxemia does not occur in pregnant women. The present invention is directed to therapeutic agents for the treatment of toxemia, preeclampsia and eclampsia and the method for preparing those agents. Further, the present invention is directed to the reduction of the formation of hydatiform moles (molar pregnancies).
More specifically, the present invention relates to stable pharmaceutical preparations containing, but not limited to, digestive/pancreatic enzymes, including, but not limited to, amylases, proteases, cellulase, papaya, papain, bromelain, lipases, chymotrypsin and hydrolases. This combination is made by, but not limited to: direct compression, microencapsulation, lipid encapsulation, wet granulation or other methods including the use of Prosolv®, microencapsulation, lipid encapsulation technology, or other suitable technology. This technology can include the use of rapid dissolution (rapid dissolve), time release or other delivery methods including oral, injection, patch or other method. Further, the delivery of the enzymes can be in the form of a tablet, sprinkles, sachet, capsules, caplets or other compressed tablet delivery, or other oral delivery method.
Further, the invention is directed toward the use of a biomarker, the presence of chymotrypsin in the maternal GI tract to determine the likelihood of developing preeclampsia, pregnancy induced hypertension, and eclampsia/toxemia.